Pathology of Skin Tumours Flashcards
What sort of biopsy is performed on potentially invasive lesions?
Excisional - curative as well
What are the histological findings of solar keratoses?
Thicker
- Can also be thinner > atrophic
Hyper-keratotic
Slightly larger basal cells
How is solar keratosis usually diagnosed?
Clinically
What are the treatment options for solar keratosis?
Cryotherapy Topical; eg: - 5-fluoruracil - Imiquinod Excision biopsy if - Concerned about invasion - Not recurrent Shave biopsy - Not helpful for therapy if extensive
What is a possible side effect of imiquinod?
Irritating > redness and burning
What information should be included in the pathology report for a skin excision?
Location Duration of lesion PHx of skin lesion Size Clinical description Indication for biopsy Previous treatment
What are the histological abnormalities of SCCs?
Nests
Keratin pearls
What are the risk factors for SCC?
Lifetime UV exposure Solar keratoses Fair skin Burn scars Chronic ulcers Renal/any transplant Road workers > exposure to tar Tobacco Arsenic Betel leaf chewing
What are the bad prognostic features of SCC of skin?
Late presentation
Relatively thick lesion
- >6 mm depth
Large size
What is the excision margin for SCC of skin?
4 mm
What is the most frequent form of skin cancer?
BCC
Where do BCCs commonly occur?
Sun exposed skin, esp - Head - Neck and trunk - Older adults May be multiple Slow growing Metastasis rare Can be locally aggressive
What are different types of BCCs?
Nodular
Superficial
Morhoeic
Basosquamous
What are the risk factors for BCCs?
Fair skin Blue eyes Immunosuppression Basal cell naevus syndrome XP = genetic syndrome Radiation
What are the bad features of BCCs?
Morphoeic type - infiltrative
Basosquamous type
Perineural invasion
Incomplete excision
What is the treatment for BCCs?
Excision = best If can't excise - Imiquinod - Efudex Cryotherapy - if must
When do benign melanocytic naevi develop?
Some congenital
Most acquired during childhood
What is the most common melanocytic tumour?
Benign melanocytic naevi
Do benign melanocytic naevi involve mucous membranes?
Sometimes
What are the macroscopic features of benign melanocytic naevi?
Small size
Circumscription
Symmetry
Do benign melanocytic naevi need to be excised?
No May be for - Cosmetic reasons - Changing - Bleeding - Concern about melanoma
What are the histological features of benign melanocytic naevi?
Small nuclei
Melanocytes decrease in size towards base of dermal component
Absence of mitotic activity
When are naevi a risk factor for melanoma?
Large numbers
What is the risk of dysplastic naevi becoming melanoma?
Of single lesion transforming = low
Multiple lesions = increased risk
What are familial dysplastic naevi syndromes?
Dysplastic naevus syndrome
Familial atypical multiple mole-melanoma syndrome
What are the features of naevi in familial dysplastic naevi syndromes?
Multiple naevi with unusualy features
Increased risk of development of melanoma
What are some pigmented lesions, other than naevi?
Freckles Lentigines Pigmented keratoses Basal cell and sometimes squamous cell carcinomas Vascular lesions - Haemangioma - Haematoma - Others Dermatofibroma Malignant melanoma
How do you differentiate between freckles and lentigines?
Freckles darken with sun exposure
Lentigines don’t darken with sun exposure
What does ABCDE stand for when identifying potentially malignant lesions?
A = asymmetry B = borders - irregular C = colour D = diameter E = evolving
For a possibly malignant lesion, what sort of biopsy should be performed?
Excision biopsy
What is the excision margin for a melanoma?
Up to 10 mm
Other than the skin, where else can melanoma occur?
Oral cavity Lip Conjunctiva Choroid Oesophagus Leptomeninges Cervix Vagina Vulva Anus
Do melanomas arise in normal skin, or an existing naevus?
Most arise in normal skin
What are the histological features of melanoma?
Atypical junctional proliferation Dermal invasion by atypical melanocytes - Not mature - Large, eosinophilic cytoplasm - Contain melanin - Large irregular nuclei - Prominent nucleoli - Frequent mitoses
What is melanoma in-situ?
Malignant melanoma along dermo-epidermal junction
May show pagetoid epidermal spread
Don’t invade dermis
= Clark level 1 melanoma
What is a red flag for a possibly malignant lesion?
Nail lesions that don’t grow out
What are the key tumour related prognostic factors in melanoma?
TNM stage
Breslow thickness
What are host related prognostic factors in melanoma?
Age Gender Site In stage IV disease - Raised serum LDH - Poor performance status
What is the relationship between Breslow thickness and risk of mortality in melanoma?
The higher the Breslow thickness, the higher the risk of mortality
Is a sentinel node biopsy performed in melanoma?
In some cases, yes
How is metastatic melanoma treated?
Surgically
Experimental chemotherapy and immunotherapy
